A common practice in forming fibers of mineral material is to pass the material in a molten state through orifices in the peripheral wall of a centrifuge or spinner to create primary fibers. Thereafter, the primary fibers are further attenuated into a veil of secondary fibers of smaller diameter by air drag attenuation from a flow of gases discharged downwardly. It is known in the prior art that the flow of gases can have high velocity in order to increase the air drag attenuation of the primary fibers into the secondary fibers. It is also known that the air drag attenuation applied to the primary fibers by the flow of gases can be greatly increased by creating some turbulence in the flow of gases.
A problem with the fiber-forming apparatus of the prior art is that the blowers used for secondary attentuation of the primary fibers into secondary fibers consume large amounts of energy since the air flows from such prior art blowers are relatively non-turbulent and, therefore, are relatively inefficient as attenuation mechanisms. Also, the blowers of the prior art do not enable the degree of turbulence to be controlled accurately. The apparatus and method of this invention are directed towards the solution of the above problems.